Power control



s[ M. UDALE POWER CONTROL Filed Jan. 31, 1942 noid 44 is mounted in acup-shaped receptacle 41 which acts as a magnet in attracting themovable armature 48 against the action of a spring 49. This spring 43tends to move the armature 48 away from the cup-shaped receptacle 41. Arod 50 is connected to the broken links and 62 so that when the currentis broken and the solenoid 44 is no longer operative to hold thearmature 48 against the cup-shaped element 41, the spring 49 pushes therod 50 upwardly.

Tracing through the gears l5, l3 and [1, it is obvious that once thelinks H and. 52 are broken, the throttle-operating lever 63 at anyposition of the manually controlled throttle lever 54 is closed, that isto say, the lever. 53 rotates-in a clockwise direction, assuming thelever 54 is stationary, and therefore the throttle It rotates in ananti-clockwise direction and the throttle 13 in a clockwise direction.By this means, whatever the position of the throttle lever 54 thethrottle will close, and even if the throtlte control lever 54 wereplaced so that the throttles l3 and M are wide open, even then thethrottles l3 and I4 will close to a point where the engine will not runaway, that is to say, the speed will not exceed the safe maximum speed,so that if for any reason the load is suddenly thrown ofi the engine,the

automatic throttle control lever 53 rotates clock-- wise, the twothrottles l3 and 14 close and the engine is held down to some safemaximum revolutions per minute of the engine.

Although the supercharger will then cease to .create the pressure atwhich the contacts 31 and 38 open, the solenoid 44 becomes active, butit is not powerful enough to attract the armature 48 and to compress thespring 49 and therefore the throttles will remain partially closed. Ifthe manually controlled throttle lever 541s moved clockwiseto close thethrottles l3 and I4 com pletely to the idle position, the lever 53engages with a stop v55 so that the lever 54, when pulled in a clockwisedirection, causes the broken links 5| and 52 to straighten out. The rod50, therefore, is pushed down by this movement of the lever 54 onto thearmature 48 and the spring 49 is thus compressed, so that once more thearmature is in place and the ,solenoid again is sufsudden closing of thethrottle during the takeoff maneuver might cause the plane to crash.

However, the device is intended primarily for use when testing theengine before taking of! and after the plane is safely in the air toprevent overloading the engine in flight.

A suitable locking device 23 is shown engaging with a guide rod 1|extending upwardly from the armature 48. v

Additional protection against an engine running away when the load isthrown off is provided by means for opening the electric circuit andreleasing the electromagnet 41 whenever the fuel flow exceeds apredetermined maximum. The reason for this additional protection is thatat high altitudes, although the supercharger pressure might not beexcessive; excessive power" could be developed, especially withmechanically driven superchargers due to the fact that the back pressurefalls. A given value for manifold air pressure gives an increasing meaneffective pressure at high altitude.

A venturi 58 in the fuel passage II will accomplish the same result andreplace the more complicated device 34-35-36-31-38-33- A pipe 51communicates the depression in the throat of a venturi 58 to a chamber58 in which a spring 59 depresses a diaphragm 60 and causes a contact 6|to engage with a contact 62, which contact is connected to the electricwire 39. An arm 63 which carries the contact BI is connected to anotherdiaphragm 64, which, in its turn, is supported-by a spring 31 mounted ina chamber 88 which is connected by a pipe 68 with a diaphragm fuelchamber 68.

An electric wire 69 is connected to the arm 63 and conducts electricityfrom a battery 10 through the contact 82, 6|, through the wire 39,

through contacts 31, 38, through the wire 40, through electric magnet44, to the ground connection 45, so that when either of the two pairs ofcontacts 38, 31or' GI, 62 are open, the throttle is automatically closedby the breaking of the broken link SI, 52. 1

. The pressure differential created by the fuel fiow increases as thesquare of the revolutions per minute. The presence createghyth'esuperchargerjz, 33 alsaincreases asth'sfquare of the revolutions perminute of the engine. Hence, when the engine is operated at sea levelthere is not need of the barometric element 36 and in fact, any otherdevice on the engine which responds to revolutions per minute can besubstituted for the supercharger pressure. It follows that a centrifugalgovernor which opens the contacts 31, 38 would be satisfactory for amarine engine. However, the primary object is to prevent an airplaneengine'being overstressed and the barometric pressure is a factor isdetermining the maximum safe speed at any speed. At low altitude a lowermaximum speed will produce excessive power, whereas at high altitudesficiently powerful to hold the part 48 in the posia higher speed of theengine is needed to produce the same power when the ceiling for theparticular supercharger is exceeded. Hence, at low altitudes, theopening of the contacts 31, 38 will protect the engine and the openingof the contacts SI, 62 will protect the engine at higher altitudes.These devices, therefore, can be used together as shown or be medseparately.

The broad idea is to break a broken link whenever the power exceeds apredetermined maximum and to compel the operator to close the throttlecompletely, that is, to the idling position before he can re-open thethrottle.

What I claim is:

1 A safety device for an internal combustion engine having an inletmanifold, a throttle valve, a manually controlled lever, a brokenlinkthrottle control connected to said lever and to said throttle valve,means for holding said broken link ing said broken link in alignment,means for releasing the holding means responsive to an increase in fuelflow in said flow responsive means above a predetermined minimum flow,and means 3. A safety device for an internal combustion engine having asupercharger, an air entrance thereto, a throttle valve therein, amanually controlled lever, a broken link connected to said lever and tosaid throttle valve, means for holding said broken link in alignment,means for remanually controlled means.

4. A safety device for an internal combustion engin having asupercharger, an air entrance to said supercharger, a throttle valvetherein, a manually controlled lever; a broken link connected to saidlever and to said throttle, fuel supply means for said engine, fuel flowresponsive means in said fuel supply means, means for hold ing saidbroken link in alignment, means for releasing said holding, meansresponsive to an increase in supercharger pressure, additional means forreleasing said holding means responsive to an increase in flow in saidfuel supply responsive means, means responsive to the movement of saidlever to the position for complete closure of said throttle forre-setting the holding means for said broken link to'permit there-opening of said throttle by said manually controlled means.

5. A device as set 'forth in claim 1 in which the holding means consistsof a source of electricity and an electromagnet including an electricsolenoid, and the means for releasing said holding 20 means consists ofa pair of separable contacts in series with an electric circuitincluding said elec-

